Body supporting structures, including for example, office chairs, vehicular and aircraft seating, sofas, beds and other pieces of furniture, are typically configured with internal or external support frames having hard contact points. For example, seats and backrests may be made with a resilient membrane or shell structure, which are typically supported by a rigid, peripheral frame surrounding the membrane or shell structure. The frame presents hard contact points, precludes flexing of the backrest or seat at the periphery thereof, and may also prevent twisting, or torsional movement, about a longitudinal axis of the backrest or seat. In other chairs, the backrest or seat may be configured with a rigid, central spine allowing for some twisting about a longitudinal axis, but with the connection of the spine to the body support member producing hard, contact points. In yet another type of chair, the backrest or seat may be configured with a rigid shell, which supports a cushion or other resilient body support member.
In all of these conventional seating structures, the rigidity of the frame or shell limits the ability of the body support structure to flex and support the body of the user as the user moves within the seating structure. Moreover, the hard contact points, or lack of flexibility at the edge of the seating structure, combined with the restrictions imposed by the frame, spine and/or rigid shell, limit the comfort and ergonomic responsiveness of the seating structure.